Poultry farmers who adopt organic practices and stop giving their birds antibiotics significantly reduce the resistance of bacteria to antibiotics in their flocks, according to a study released Wednesday.

Public health experts have become increasingly concerned about germs becoming resistant to many commonly used antibiotics. In fact, an outbreak of salmonella currently occurring is being caused by a resistant strain of the bacteria traced back to ground turkey.

In the new study, published in the journal Environmental Health Perspectives, Amy Sapkota of the University of Maryland School of Public Health and colleagues studied 10 conventional farms and 10 farms that had recently become organic in 2008. They tested for the presence of a bacteria known as enterococci in poultry litter, feed and water and for whether the organisms were resistant to 17 commonly used drugs.